Torn by Mary Brock Jones

Two ecological engineers must change their world to save it, no matter the cost to all they love.
Fee comes from the mountains of her world. She grew up with trees, rushing streams and rain. The grasslands beyond the foothills are Caleb’s home. Dry, windblown, a place of endless light and untouchable horizons.
Both are ecological engineers for the Survey, working to save their world from environmental disaster before it’s too late. Because unless something is done, soon, the planet is going to hit back. Storms, floods, drought. Don’t bother taking your pick, says the planet, you’re going to get the lot.
Only the men and women of the Survey hear the call, working in secret for years to heal Arcadia’s wounds. Now the Survey has a plan to save their world. Fee and Caleb must make lakes where dusty grasses rule; meadows where dense forest stands, all without their profit-geared families finding out until it’s too late to stop them. An impossible task surely, when all they have in common is the love both have for their home regions and the lies they must tell the families who love them.
But why Fee and Caleb, and what does the Survey truly plan for them?